System for controlling flushing of a cistern

ABSTRACT

A control system for a cistern, the control system comprising a user activated sensor (13), a controller (14), a pump (15) and a pneumatic line (16) connected to the pump (15) and adapted to be connected to the drain valve (11) of a cistern (10), wherein the user activated sensor (13) and controller (14) are adapted to interpret a plurality of signals and operate the pump (15) in a pre-defined manner associated with a detected signal, thereby enabling a plurality of flushing actions to be effected using a single user activated sensor.

This invention relates to a cistern for a toilet, urinal or the like. Inparticular, the invention relates to a control system for controllingthe flushing of such a cistern.

Various forms of flushing mechanism exist. Conventionally, flushing of acistern is effected by operating a drain valve. It is known to use apneumatic or hydraulic actuator to operate the drain valve. Actuation istypically effected externally of the cistern.

Dual flushing cisterns are known. These typically comprise two actuatorseach causing the flushing of a different volume of water through thecistern. For example, this may be a small volume (sometimes described as“partial”) flush if flushing fluids and a large volume (sometimesdescribed as “full”) flush if flushing solids. The actuators aretypically controlled by manually operated activators positionedexternally of the cistern, for example, the actuators may be a handle,push button or sensor which responds to some form of signal provided bya user.

An example of an existing dual flush cistern is described in EP 1 582637 of Valsir S.p.A. In that cistern, a drain valve has associated withit two pneumatic actuators each comprising a bellows. The bellows are ofdifferent proportions and control respectively a partial or a full flushof the cistern. Each bellow has an inlet sleeve and a connecting memberacting on the drain valve. The inlet sleeve of each bellows connectswith a distributor which in turn connects with two buttons, each ofwhich when depressed, actuates an associated pneumatic pulse generator.Each button and pulse generator is connected with a single one of thepneumatic actuators via the distributor. The user makes a choice as towhich is an appropriate flushing action and presses the appropriatebutton which actuates the appropriate bellows causing the requiredflushing action.

The present invention seeks to provide a control system for controllingflushing of a cistern which is less intrusive than the prior art systemand which has improved functionality.

In accordance with the present invention there is provided a controlsystem for a cistern, the control system comprising a user activatedsensor, a controller, a pump and a pneumatic line connected to the pumpand adapted to be connected to the drain valve of a cistern, wherein theuser activated sensor and controller are adapted to interpret aplurality of signals and operate the pump in a pre defined mannerassociated with a detected signal, thereby enabling a plurality offlushing actions to be effected using a single user activated sensor.

The user activated sensor may take any of a variety of forms; forexample but without limitation, it may be responsive to pressure, light,touch or motion. In another alternative, the sensor may be soundsensitive. The controller is configured not only to recognise that asignal has been detected by the sensor but to monitor the duration orother extent of the signal. Having recognised a pre defined signal, thecontroller interprets this signal into a previously defined pneumaticpulse action which causes an appropriate degree of opening of the drainvalve.

The system may be adapted to respond to a variety of hand signals. Forexample but without limitation, waving hand, still hand, single touch,touch and hold, push, push and release, or push and hold. Alternatively,it may respond to certain noises, including but not limited to speech,hand clapping, whistles and the like.

One embodiment of the user activated sensor comprises a PCB whichincorporates an infra red sensor and a plurality of light emittingindicators. The light emitting indicators can be displayed in any predefined manner to give an indication of the current status of thesystem. For example, but without limitation, a blue light may be used toindicate a whole flush is being performed and a green light to indicatethat a partial flush is being performed, a flashing light in any colourmay indicate the system is resetting after flushing or that the systemis monitoring other parts of the flushed system, for example the waterlevel. In this embodiment, the various light emitting indicators and theinfra red sensor or housed behind a bespoke, multi-layer lens, eachlayer comprising an emulsion selected to transmit a frequency of lightwhich corresponds to a frequency emitted by one or more of the lightemitting indicators and the infra red transmitter/receiver. Thisarrangement is advantageous in that it permits all signalling/sensingcomponents to be housed collectively on a compact PCB and protected fromexternal environmental influences.

In another embodiment the user activated sensor is associated with amechanical device which is operated by a user. For example, the sensormay be associated with a Victorian style pull chain flush or rotaryhandle flush. In such an embodiment, the user operates the pull chain orhandle which in turn causes interaction with the sensor and performs anappropriate flush. Since the extent of any action on the pull chain orhandle is transferred to the sensor and monitored by the controller. Asystem traditionally not configured to perform ecologically efficientflushing actions can be made to perform more ecologically efficientflushing actions, i.e. a system designed with a single flushing actioncan be adapted to perform multiple flushing actions.

The control system may further include sensors for monitoring the watervolume in a lavatory bowl or cistern. With an appropriately configuredcontroller, the system can then be adapted to intelligently perform themost economical flush irrespective of the extent of a detected signal,i.e. to use a minimum appropriate amount of water to provide aneffective flush given the current condition of the water in a lavatorysystem. Optionally, the controller may be configured not to permitflushing unless certain conditions are present. Optionally also thecontroller may be configured to perform a partial flush if moreappropriate, even if signal is for a full flush. In another option, thecontroller may be adapted to cause reverse as well as forward action ofthe pump; this may be useful in addressing blockages or water shortagesin the system.

Optionally, a plurality of pumps may be associated with the single useractivated sensor. Each pump being effective to cause a different flush,for example, there may be two flushes, one to cause a partial flush andthe other a full flush. In the manner previously described, thecontroller elects the most appropriate flush in reaction to sensorinputs and activates the appropriate one of the plurality of flushes.

Ideally, the system is powered by a low voltage supply. 4V and 6 volt DCsupplies have been found quite adequate for powering some embodiments ofthe invention. Consequently the system is very economical to use. Thepower supply can optionally be selected from a battery or transformedmains electricity, thereby minimising the risk of electrocution in theevent of malfunction.

In another option, the controller is configured to counteract areduction in power supply by increasing the duration of a pneumaticpulse to the pump, thus, irrespective of the power of the pulse, thevolume of air and consequent volume of water in a given type of flushare maintained fairly constant.

An optional additional feature to the embodiments described involvesincorporating a clock within the controller which monitors a predefinedperiod of time since the last flush of the system. For example butwithout limitation, the timer may be programmed at 12 hours. In such anembodiment, say in an office toilet facility, if the last flush was atabout 6 pm as the last office worker left the building, the system wouldautomatically flush at around 6 am, freshening the system before thearrival of the first office worker the next morning.

It will be appreciated the proposed system is particularly portable andadaptable and can be quickly and easily retrofitted to existing draintanks. The controller can be programmed to a user's specificationenabling the user to choose his preferred mode of signalling for a fullor partial flush and even to elect the specific parameters of a full orpartial flush.

It will be appreciated that the system of the invention may have widerapplication in any apparatus where periodic sharp injections ofpressurised air may be used to perform or effect a desired function.

Some embodiments of the invention will now be further described withreference to the following figures in which:

FIG. 1 shows a first embodiment of a cistern embodying a control systemin accordance with the present invention.

FIG. 2 shows second and third embodiments of a cistern embodying acontrol system in accordance with the present invention.

FIG. 3 illustrates schematically a printed circuit board PCB suitablefor use as a controller and user activated sensor in a control system inaccordance with the invention.

FIG. 1 shows a cistern composed of a reservoir of water 10 connected viaconduit and a pneumatically actuated valve 11 to a toilet 12. Thecistern is provided with an infrared proximity and motion sensor 13which detects the presence of a user's waving hand (not shown)signifying a desire to flush the toilet. Upon receiving a correspondingsignal from the sensor, control logic 14 supplied with a 6V batterypower supply causes the pneumatically actuated valve to open, therebycausing the toilet to flush. As previously mentioned a 4V battery powersupply has also been found to be effective.

Specifically, the control logic 14 outputs the power supply to a pump 15which in turn pumps air in to flexible pneumatic lines 16 connectedbetween the pump and the pneumatically actuated valve 11. Thepneumatically actuated valve 11 is then caused to open when the staticpressure in the pneumatic lines reaches a threshold. Depending on theduration of the increased pressure in the pneumatic line, partial orfull flushes may be achieved.

Connected to the pneumatic lines 16 is a solenoid valve 17 which in anunpowered state allows release of pressure in the pneumatic lines. In apowered state, which occurs when the pump is powered, the solenoid valveis closed.

Also connected to the pneumatic lines 16 is a safety valve 18 whichopens when the static pressure in the pneumatic lines exceeds aparticular threshold (in excess of that necessary to cause the pneumaticactuator valve 11 to open).

The above embodiments use an infrared proximity and motion sensor butother modes of control are contemplated including the use of a timer andmanual switching. In the present embodiment, the infrared sensor isresponsive to a hand waving signal and a stationary hand signal. When awaving hand signal is detected, the controller prompts actuation of apneumatic pulse of short duration causing a partial flush of the system.In response to a stationary hand signal, the controller prompts apneumatic pulse of longer duration and a full flush of the system.

As previously discussed, the system may include other sensors and asuitable adaptation of the controller which enables the controller tointelligently determine whether the instructed flush is necessary or themost ecologically efficient flush given the current condition of thewater in the lavatory system. The controller is thus enabled to overrideinstructions for inappropriate flushes.

FIG. 2 shows an alternative embodiment of the invention. As can be seenfrom FIG. 2,

In common with FIG. 1, FIG. 2 show a cistern composed of a reservoir ofwater 10 connected via a conduit and a pneumatically actuated valve 211to a toilet 212. The cistern is provided with a user activated sensor213 which detects a user provided signal signifying a desire to flushthe toilet in an elected manner (e.g. full flush or partial flush). Thesensor may be a motion sensor, pressure or touch sensitive, lightsensitive or sound sensitive. Upon receiving a corresponding signal fromthe sensor, the controller 214, powered by a battery supply with of 4 to6V determines an appropriate flushing action and operates theappropriate one of pumps 215 a and 215 b, thereby causing the toilet toflush.

Specifically, the controller 214 outputs the power supply to one of thepumps 215 a and 215 b which in turn pumps an appropriate volume of airin to flexible pneumatic lines 216 connected between the pumps and thepneumatically actuated drain valve 211. The drain valve 211 is thencaused to open when the static pressure in the pneumatic lines reaches athreshold. Duration of the increased pressure in the pneumatic line andconsequent volume of air transferred differs for each pump allowing apartial or full flush as appropriate.

Connected to the pneumatic lines 216 and associated with each pump 215a, 215 b is a solenoid valve 217 which in an unpowered state allowsrelease of pressure in the pneumatic lines. In a powered state, whichoccurs when the associated pump is powered, the solenoid valve isclosed.

The broken line illustrates an optional additional sensor and itscommunication with the controller. As previously discussed the optionalsensor monitors water levels in the cistern and the controller mayoverride a flushing instruction provided manually via the user activatedsensor to ensure flushing is ecologically efficient.

As can be seen from the FIG. 3, a PCB includes a control chip 30communicating with an infra red transmitter 31, infra red receiver 32,first coloured LED 33 and second coloured LED of different colour 34.The dotted line shows the position of a suitably configured lens 35which allows transmission of infra red and lights of the frequenciesemitted by the LEDs.

From reading the present disclosure, other modifications will beapparent to persons skilled in the art. Such modifications may involveother features which are already known in the design and use ofpneumatic control systems and component parts thereof and which may beused instead of or in addition to features already described herein.

1. A control system for a cistern, the control system comprising a useractivated sensor, a controller, a pump and a pneumatic line connected tothe pump and adapted to be connected to the drain valve of a cistern,wherein the user activated sensor and controller are adapted tointerpret a plurality of signals and operate the pump in a pre definedmanner associated with a detected signal, thereby enabling a pluralityof flushing actions to be effected using a single user activated sensor.2. A control system as claimed in claim 1 wherein the user activatedsensor is a motion detector.
 3. A control system as claimed in claim 1wherein the user activated sensor is a pressure or touch sensor.
 4. Acontrol system as claimed in claim 1 wherein the motion detector is aninfra red proximity sensor.
 5. A control system as claimed in claim 1,wherein the system further comprises a pressure release valveincorporated in a pneumatic line and which is configured to close whenthe pump is powered and to open when the pump is not powered.
 6. Acontrol system as claimed in claim 1, further including one or moresensors for monitoring the water volume in the water filled system whichis to be flushed and wherein the controller is appropriately configuredto determine and effect the most economical flush of the water filledsystem.
 7. A control system as claimed in claim 6 wherein the controlleris configured to override a received flush signal if the flush signaldoes not demand the most economical flush.
 8. A control system asclaimed in claim 1, wherein the controller is adapted to cause reverseas well as forward action of the pump in response to appropriatesignals.
 9. A control system as claimed in claim 1, which is powered bya low voltage DC supply.
 10. A control system as claimed in claim 9wherein the power supply is a 6V battery.
 11. A control system asclaimed in claim 9 wherein the power supply is a 4V battery.
 12. Acontrol system as claimed in claim 1, which includes a plurality ofpumps each configured to cause a specific and pre defined flushingaction and wherein the controller associates each pump with a differentsignal received by the user activated sensor and elects an appropriatepump to operate in reaction to a detected signal.
 13. A control systemas claimed in claim 1, wherein the controller is configured tocompensate for any variation in the power supply by adjusting theduration of a pneumatic pulse to the pump, such that, irrespective ofthe power of the pulse, constancy of the volume of air and consequentvolume of water in a flush are maintained.
 14. A control system asclaimed in claim 1, wherein the user activated sensor comprises an infrared transmitter/receiver and is embodied with the controller in a PCBwhich also houses one or more light emitting indicators, the controllerbeing configured to activate the or each light emitting indicator in apre defined manner to give an indication of the current status of thesystem.
 15. A control system as claimed in claim 14 wherein the infrared transmitter/receiver and one or more light emitting indicators areenclosed behind a multi-layer lens, each layer of the lens comprising anemulsion selected to transmit a frequency of light which corresponds toa frequency emitted by one or more of the light emitting indicators andthe infra red transmitter/receiver.
 16. A control system as claimed inclaim 14, including two light emitting indicators and the controllerbeing configured to display a first of the indicators during a partialflush and the second during a whole flush.
 17. A control system asclaimed in claim 16 wherein the light emitting indicators are blue andgreen LEDs.
 18. A control system as claimed in claim 1, wherein thecontroller incorporates a timer which monitors a pre defined periodsince the last flush of the system generates a flush at the expiry ofthe pre defined period and resets after each flush of the system.
 19. Alavatory cistern incorporating a control system as claimed in claim 1.20. A lavatory cistern as claimed in claim 19 wherein the user activatedsensor is associated with a mechanical pull chain or handle and whereinoperation of the pull chain or handle is translated into a signal towhich the user activated sensor is receptive.